Ignition Conditions Research Articles

Combustion and Exhaust Emission Improvement in a 3-Cylinder Mpfi Engine Through Downsizing

This research aims to compare the potential and existing conditions of a small-sized spark ignition (SI) engine with a 1.0-liter capacity suitable for cylinder deactivation. The cylinder deactivation strategy is used to solve the issues of inefficient combustion and increased exhaust emission under part loading. Consequently, the possibility of implementing cylinder deactivation in terms of decreased exhaust pollution has been assessed. A computerized, 1.0-liter, 4-stroke, water-cooled, spark-ignition engine with an open engine control unit (ECU) and multi-point fuel injection (MPFI) was used for the trials. Both modes were tested at 2500 revolutions per minute (RPM) under loads of 15, 30, and 45 N-m. The spark plug and fuel injector deactivate the cylinder. The results show that when the highest possible load is used, the peak cylinder pressure is 55.78% higher, and the maximum heat release rate is 53.96% more in the deactivation mode than in the traditional mode. In deactivation mode, the mass fraction consumed is larger at each crank angle point, suggesting a faster rate of combustion and increased combustion efficiency. The increased mean gas temperature permits the catalytic converter to perform more efficiently after downsizing. When compared to the conventional mode, carbon monoxide (CO) emission is almost non-existent at full load, unburned hydrocarbon (UHC) is reduced by 92.89%, and oxides of nitrogen (NOx) are reduced by 35% in the deactivation mode. Furthermore, the experiment indicated that, when employed at part load, the deactivation mode is more beneficial than the standard mode in terms of better combustion stability and lesser emissions.

Mathematical Modeling of Water-Coal Fuel Droplets Ignition Under High Pressure Medium

ABSTRACT The article presents the results of theoretical studies of the ignition process of a water-coal fuel particle under conditions of high-temperature heating at high pressures of the external environment. The authors have developed a new mathematical model of the water-coal fuel particles ignition under stress (pressure – Pg = 1–200 bar, and temperature Tg = 873–1273 K) heating conditions. The mathematical model differs from the known ones by a detailed description of the physicochemical processes occurring during the induction period of time, as well as the processes of phase transitions under high pressure conditions. Based on the results of numerical simulation of the ignition process, it was found that the pressure of the external environment (Pg) has a significant effect on the characteristics and conditions of ignition of water-coal fuel particles. It was shown that the tign(Pg) dependence is essentially nonmonotonic. The authors have established that when Pg changes in the range from 1 to 30 bar (for oxidizer temperatures (Tg = 873–1273 K), an increase in the ambient pressure leads to a nonmonotonic increase in tign. In this way such a dependence tign(Pg) is due to the joint influence of two significant parameters of the factor space, which significantly affects the dynamics of the thermal treatment of fuel. With an increase in the pressure of the mixture of oxidizer and combustible gases, the saturation temperature (the temperature of intense evaporation of water) increases, at the same time, the heat of the phase transition (QL) decreases and the rate of release of pyrolysis gases into the oxidizing environment decreases. Based on the results of the theoretical studies, it has been shown that for efficient combustion of water-coal fuel under the conditions of the combustion chambers of a GT at oxidizer temperatures Tg≥1073K, the pressure in the combustion chamber of the GT must be at least 50 bar.

Numerical investigation on the shock wave propagation, hydrogen/air mixing and spontaneous ignition induced by high-pressure hydrogen release inside the tubes with different shaped cross-sections

Hydrogen is regard as one of the most promising primary energy vectors solving the problems of air pollution and energy shortage. However, the spontaneous ignition is a major hazard during the application of high-pressure hydrogen. In this paper, a numerical investigation is conducted to study the shock wave propagation, hydrogen/air mixing and spontaneous ignition induced by high-pressure hydrogen release into the tubes with square, pentagon and circular cross-sections (tube wall angles are 90, 108 and 180° respectively). Large Eddy Simulation, Eddy Dissipation Concept coupling with the detailed hydrogen/air reaction mechanism and 10-step like opening process of burst disk are employed. The numerical results of ignition conditions and positions agree well against the previous experimental results. In the square and pentagon tubes, the inward-reflected and outward-reflected shock wave could be generated simultaneously and interact with each other due to the radial propagation of leading shock wave. In the circular tube, however, the two types of reflected shock generate alternately and the interaction disappears. The higher viscous resistance at wall corner induces the formation of velocity shear layer on the tube wall, which promotes the mixing of hydrogen and air. The increase of the angle of wall corner reduces the flammable mixture with the chemical equilibrium equivalence ratio on the tube wall due to the low viscous resistance and short velocity shear layer. The ignition delay time/distance and combustion intensity decrease with the increase of the angle of wall corner. After the occurrence of spontaneous ignitions in the non-circular tubes, the flame propagates downstream and its length increases rapidly along the wall corner. In addition, larger combustion area could be observed with the decrease of the angle of wall corner.

ABOUT THE POSSIBILITY OF USING THERMOCHEMICAL GAS ANALYZERS IN A MULTICOMPONENT MIXTURE

Kinetic parameters finding’s method of heterogeneous catalytic oxidation reactions of combustible gas’s small impurities in air on a thin platinum wire was described. It consists in obtaining from the wire’s current-voltage characteristic the dependence of the critical current values on its mass fraction in air. They corresponding to the catalytic ignition and extintion of the gas impurity. A method of determining the content of two combustible gases in the air, what based on processing the platinum wire’s current-voltage characteristic, was proposed. Depending on the level of the total gases concentration in the air, the determining experimental characteristics are not only the wire (catalyst) overheating relative to the inert wire under the conditions of catalytic ignition, but also the wire overheating during catalytic extinguishing or under conditions of self-sustaining catalytic combustion (without electric current heating).

Experimental study on the combustion process of a kerosene-fueled scramjet with strut injection

The ground combustion test was used to study the effects of kerosene fuel on the start-up ignition and flame stabilization of a scramjet with reverse strut injection. The test analyzed the changes of flow field wave system and flame propagation law under various working conditions after pilot hydrogen was injected into the combustor. The results showed that when hydrogen was injected into the combustor, it started to combust in only 0.0128 s. The heat released by combustion led to the generation of reverse pressure gradient, which made the wave system move forward and concentrate near the backward step. In the case of hydrogen self-ignition, the entire flow field remained stable combustion. At t = 0.07 s, kerosene was gradually injected into scramjet and ignited by pilot flame. The pressure at the monitoring point increased rapidly from 0.064 MPa to 0.135 MPa, and severe combustion occurred in the cavity. The flame began to propagate from the shear layer to the low-speed recirculation zone. Subsequently, the pressure of the monitoring point was reduced to 0.121 MPa, and the combustion flame continuously passed from the cavity downstream. When the hydrogen was removed, the pressure was reduced to 0.09 MPa, and the flame in the cavity was relatively weakened. However, the rapid ignition condition of kerosene could still be achieved, and the combustion flame continued to generate. After fuel began to be gradually removed, kerosene could not maintain continuous flame combustion due to the reduction of injection volume. The combustor changed between ignition and flameout, showing periodic oscillation with a period of 4.8 ms.

Heat and mass transfer at the ignition of single and double gas hydrate powder flow in a reactor

This paper details the heat and mass transfer at the ignition patterns of single (methane) and double (methane-isopropanol) granulated hydrates in a heated air. The experiments were performed in a laboratory-scale combustion chamber in the form of an oblong reactor with free-falling powder of the gas hydrate granules. The air in the combustion chamber was heated by the walls with ceramic plate heaters. The variation ranges of the input parameters were chosen to match the capacities of modern energy generation systems. We established the ignition delay times of the gas hydrate granules, combustion regimes, and sizes of the flame zone behind moving granules. We also analyzed the joint influence of the gas hydrate granules on their ignition behavior. A model was developed to estimate the threshold boundary conditions of gas hydrate ignition in different-sized chambers, with variable hydrate component composition granule size. Gas hydrate dissociation rates were determined in different sections of the laboratory-scale combustion chamber. Thermal conditions were predicted in which gas hydrates consistently ignite in combustion chambers with minimum cooling of the chamber walls and minimum unburnt fuel.

Investigation on NO reduction behavior within complex atmosphere during pilot ignition of low calorific gas

Low calorific gas (LCG) is largely produced in industries and agricultures, but its utilization is difficult due to the poor combustibility and high NO x emission. The pilot ignition combustion has the potential to improve LCG’s combustibility and also reduce NO production with combining air stage approach. However, the complex atmosphere created under pilot ignition condition could complicate the NO reduction (by CH4) behavior and should be clarified. This paper is aimed at gain a deep insight on this issue by exploring the interaction between temperature and atmosphere, the individual role of α and CH4 concentration (or its ratio to NO), and the influence of CO and CO2 presence. The results show that with dropping α, the maximum NO reduction ratio increases, but a higher temperature is needed to achieve this value. Under fuel rich condition, NO reduction was accompanied with HCN formation, which must be considered to analyze the effective reduction. The CO2 generated from pilot flame or originally contained in LCG could inhibit the NO reduction, with this effect being more pronounced at a fuel rich atmosphere. For a CO/CH4 duel reactive LCGs, CO reduces the NO reduction ratio at lower temperature, but improves at higher temperature.

Comparative study of ignition characteristics and engine performance of RP-3 kerosene and diesel under compression ignition condition

This paper aims to explore the spontaneous combustion characteristics and engine performance of kerosene under traditional compression ignition mode, providing a reference for further optimizing the performance of kerosene compression ignition engines and the application of advanced combustion mode. The ignition visualization tests of kerosene under marine and vehicle engine conditions are carried out, and the characteristics under 0.3 mm nozzle diameter are compared with that of diesel. Then, the engine performance of the two fuels under medium load and ultra-high injection pressures is compared. The experimental results show that the ignition and combustion characteristics of kerosene and diesel are very similar, indicating that kerosene has a strong universality in diesel engine application. The long ignition delay time of kerosene leads to its lagging combustion and heat release. Compared with diesel, kerosene has lower CO, particulate emissions and indicated thermal efficiency, while higher HC and NOx emissions. The emission characteristics of kerosene RP-3 are different from previous studies, especially under ultra-high injection pressure. The combustion process and engine emissions of kerosene may be optimized with advanced combustion models and strategies.

A Theoretical Description of the Ignition Conditions for TC17 Alloy in Oxygen-Enriched Atmospheres

ABSTRACT Titanium alloys can be ignited under extreme conditions including high pressure, high temperature, and high-speed friction. A theoretical description of the ignition conditions for titanium alloys is critical for their safe use in aerospace industries. In this study, a chemical-absorption-controlled ignition model for bulk TC17 alloy in oxygen-enriched atmospheres was developed based on Semenov’s thermal ignition theory. The adsorption coefficient, reaction order, and activation energy for the ignition of TC17 alloy were obtained by fitting the model with the experimental critical oxygen pressure and critical ignition temperatures. The fitting results showed that the chemical-absorption-controlled ignition model fitted better with the experimental data compared with the diffusion-controlled ignition model, implying that the ignition process was controlled by chemical absorption rather than oxygen diffusion through the oxidation layer. Moreover, the activation energy for the ignition of TC17 alloy bars was obtained to be 50.01 kJ/mol, which was only less than one-fourth of that of non-isothermal oxidation (231.98 kJ/mol), indicating that the ignition requires much lower activation energy than oxidation. The chemical-absorption-controlled ignition model successfully predicted the ignition temperature of TC17 alloy bars with different diameters with the relative error within 4.41%, demonstrating the validity of the model.

Influence of a cubic wood particle orientation in space on the characteristics and conditions of its ignition

The article presents the results of the experimental and theoretical studies of the ignition processes of dry particles of woody biomass with a wide variation in heating conditions. A detailed analysis of the typical frames of the videogram has shown that the temperature of the oxidizing agent affects the nature of the ignition process of a wood particle. Under conditions of moderate ambient temperatures (Tg ≤ 873K), ignition, as a rule, occurs in the gas region under the particle. At the same time, the ignition of wood particles under conditions of high-temperature heating (at Tg > 1073K) proceeds in the gas phase in a small (very thin) neighborhood around the wood particle along its entire perimeter.A model is formulated that describes the ignition under the considered rather typical conditions and differs from the known description of the processes of convection of gaseous pyrolysis products during the induction period. Based on the results of the experiments, the influence of the type of woody biomass on the characteristics and conditions of ignition of fuel particles has been analyzed. It has been established that dry particles of woody biomass made of pine under relatively low ambient temperatures (at Tg≤873 K) ignite much faster compared to particles of similar size from birch, aspen and cedar. Differences in ignition delay times reach 90%. At high ambient temperatures (Tg≥1273K), the ignition delay times of all four investigated fairly typical types of woody biomass differ insignificantly (the deviation of the ignition delay times does not exceed 5%).The analysis of the influence of the orientation of wood fibers in space relative to the direction of the heat flow vector on the characteristics and conditions of ignition has also been carried out. It is shown that the orientation of the wood particle in space does not significantly affect the characteristics and conditions of ignition. This trend has been registered for all four types of wood studied.

Accounting for speckle-scale beam bending in classical ray tracing schemes for propagating realistic pulses in indirect drive ignition conditions

We propose a semi-analytical modeling of smoothed laser beam deviation induced by plasma flows. Based on a Gaussian description of speckles, the model includes spatial, temporal, and polarization smoothing techniques, through fits coming from hydrodynamic simulations with a paraxial description of electromagnetic waves. This beam bending model is then incorporated into a ray tracing algorithm and carefully validated. When applied as a post-process to the propagation of the inner cone in a full-scale simulation of a National Ignition Facility (NIF) experiment, the beam bending along the path of the laser affects the refraction conditions inside the hohlraum and the energy deposition, and could explain some anomalous refraction measurements, namely, the so-called glint observed in some NIF experiments.

Ignition characteristics of methane-air mixture at low initial temperature

In this paper, FLUENT software coupled with the chemical reaction mechanism is used to study the ignition characteristics of methane-air mixtures at low temperature. Variations of the main free radical concentrations, the critical conditions for a successful ignition and the chemical reaction rate of each elementary reaction for a failure ignition are obtained, respectively. Results indicate that the consumption of methane immediately affects the concentration distribution of carbon monoxide, which presents the opposite relationship with that of methane. Mass fractions of the intermediate products and H, O free radicals are low in the burnt zone and unburnt zone, whereas reach the maximum on the flame front. OH is not only the intermediate free radical, but also the combustion product remained by the intermediate reactions. At a low temperature of 150 K, the critical radius and temperature of methane ignition are 4.6 mm and 1180 K, respectively. When ignition radius is smaller than the critical value, the failed ignition of methane is caused by the termination of the elementary reactions: R8: H + O2 = OH + O, R9: OH + O = O2 + H, R12: O + H2O = 2OH and R13: 2OH = O + H2O. However, when ignition temperature is lower than the critical value, because of the failed initiation of elementary reaction R1: CH4 = CH3 + H, the combustion of methane is not occurred.

Influence of Dust Layers in Connecting Pipes on Explosion Propagation Characteristics of Flake Aluminum Powder in Cylindrical Interconnected Vessels.

Aluminum dust explosion has become an important type of dust explosion accident. In the present work, an interconnected system is established to study the influence of accumulated dust layers in connecting pipes on explosion propagation characteristics. A high-precision computational fluid dynamics (CFD) method is applied to study the overpressure and flame development of aluminum powder explosion under the central ignition condition of two cylindrical vessels with a volume ratio of 1:5. The results show that pressure build-up in the secondary container is mainly due to the oscillating pressure wave. Moreover, compared with the ignition container, the thickness of the dust layer has a more obvious enhancement effect on the peak overpressure for the secondary container. When the ignition occurs in a large container, the dust layer is lifted in the connecting pipe under the action of the precursor pressure wave. After the jet flame enters the connecting pipe, the lifted aluminum dust participates in the explosion reaction, which significantly increases the explosion intensity. With the participation of the accumulated dust layer, the maximum overpressure of the explosion of flake aluminum dust in the interconnected system is higher than 30 bar, and the jet flame velocity is increased by 3 times. The present work can provide reference for the safety design of process equipment involving dust.

Macroscopic and mesoscopic properties of HTPB propellant under low temperature dynamic biaxial compression loading

In order to study the macroscopic mechanical properties and meso damage mechanism of solid fuel hydroxy-terminated polybutadiene (HTPB) propellant under low temperature and dynamic biaxial compression loading, the INSTRON high strain rate hydraulic testing machine was used to carry out dynamic biaxial compression test of HTPB propellant in the temperature range of −50 °C ∼ -30 °C and the strain rate range of 1s−1–85s−1. Meanwhile, the control test at room temperature (25 °C) was set up, and microcomputed tomography (Micro-CT) was used to observe and quantitatively characterize the meso damage of the loaded specimens. The test results show that temperature and strain rate significantly affect the mechanical properties of HTPB propellant in biaxial compression, and the mechanical properties under biaxial compression loading are more susceptible to temperature than strain rate. In addition, there is a significant difference between uniaxial and biaxial strength under compression loading, and finally, the effect of temperature and strain rate on mechanical properties is closely related to the variation in properties and mesoscopic damage mechanisms of HTPB propellants. This paper can deepen researchers' understanding of the performance of composite solid propellant and other energetic materials at the macro and micro level, and provide more effective theoretical and technical support for accurate analysis of the grain structure integrity of airborne missile solid rocket motor (SRM) under low temperature ignition conditions.

Influence of homeomorphism of the surface of a wood particle on the characteristics of its ignition

The article presents the results of the experimental studies carried out to analyze the connections between the configuration of the particles and the delay time of their ignition. The results of the experimental studies of the ignition processes of woody biomass particles of various shapes and sizes, but identical volumes, as applied to the heating conditions in the combustion chambers of the typical boiler units, are obtained. Three shapes of wood particles were studied: a rectangular parallelepiped, a cube, and a plate. Quite non-obvious (based on traditional concepts) dependences of the ignition delay times on the characteristic sizes of wood particles have also been established: under conditions of relatively low ambient temperatures (Tg = 873K), the characteristic size and shape have a significant effect on the characteristics and conditions of ignition. In the case of ignition of plates, the dependence tign(δ) is linear; in the case of ignition of cubic particles, the dependence tign(δ) is nonmonotonic with a local minimum; in the case of ignition of biomass particles in the form of parallelepipeds, the function tign(δ) has a nonmonotonic character with a local maximum of the value of tign.

Исследование особенностей зажигания и горения высокоплотных зарядов в условиях постоянного объема

The study of combustion and ignition of charges with promising propellants or powder compositions in terms of initial conditions is an urgent problem of modern ballistics. Generally, combustion and ignition of charges are tested in a manometric closed vessel. The charge ignition conditions may affect the subsequent reactions. When designing a shot with a new charge, it is necessary to know what determines the moment of ignition (gas pressure, time, pressure rise rate, type of igniter, etc.) and which factor has a greater effect on the ignition. This paper presents a study of some features of high-density charge ignition under constant volume conditions. A brief description of the manometric setup is given. The effect of mass and type of igniter and combustion surface area on the high-density charge ignition and subsequent combustion is studied. The pressure-time dependences corresponding to high-density charge combustion in a textolite container with different diameters are presented and analyzed. The ignition of the paste high-density charge is revealed to be affected by the geometric dimensions of the container. The parametric experimental study results show that the ignition conditions of a model high-density propellant (MHDP) strongly depend on the method of initiation, namely the number of burning particles and ambient pressure; however, these factors do not affect the dependence of the MHDP combustion rate on pressure. The ignition momentum is obtained as a function of the ratio of the container burning surface circumference to the burning surface area.

Influence of mass ablation on ignition and burn propagation in layered fusion capsules

After decades of research, recent laser-driven inertial fusion experiments have demonstrated rapid progress toward achieving thermonuclear ignition using capsule designs with cryogenic fuel layers. The ignition physics for these layered capsules involves a complex interplay between the dynamically forming hot spot and the dense surrounding fuel. Using analytic theory and numerical simulations, we demonstrate that the mass ablation rate into the hot spot depends sensitively upon the temperature of the dense fuel, resulting in ablative inflows up to 4× faster than previous estimates. This produces an enthalpy flux into the hot spot that plays a critical role in controlling the hot spot temperature, the ignition threshold, and the subsequent burn propagation. The net influence of mass ablation on the ignition threshold is regulated by a dimensionless parameter that depends upon the temperature of the dense fuel. As a consequence, the ignition threshold is sensitive to any mechanism that heats the dense fuel, such as neutrons or radiation emitted from the hot spot. These predictions are confirmed using radiation-hydrodynamic simulations for a series of capsules near ignition conditions. This analysis may have relevance for understanding the variable performance of recent experiments and for guiding new capsule designs toward higher fusion yields.

DEVELOPMENT AND USE OF A MODULAR HEATER OF INTERNAL COMBUSTION ENGINE FOR MULTI-PURPOSE VEHICLES

The operation of power facilities in winter, characterized by low ambient temperatures reaching minus 50 degrees Celsius, requires their adaptation to work in such conditions. With a decrease in the ambient temperature, the vaporization of gasoline also worsens, the ignition conditions of the working mixture in the cylinders of diesel cars change, the power consumption of batteries increases when starting a cold engine. (Research purpose) The research purpose is conducting a patent search and creating a reliable, highly efficient thermoelectric heating device with a low cost, which allows improving the performance of a power vehicle (car) working in winter conditions. (Materials and methods) The KamAZ-55111 car, adapted to low-temperature conditions of use, with a thermoelectric heating module installed, was studied. The tests were carried out according to generally accepted general and particular methods using specialized mathematical calculation programs, experimental modeling and regression analysis methods. (Results and discussion) It was determined that when the engine is running, the exhaust gases heat the exhaust pipe and the surface of the device installed on it with the Peltier element. When the vehicle is moving, the temperature difference increases with the flow of cold air, which provides an increase in electrical energy for charging the traction alkaline battery, then through the controller to the electric heating element for heating and maintaining the optimal temperature of the working fluids and components of the car. It was found that the heating time of the hydraulic cylinder working fluid from minus 40 to plus 30 degrees Celsius was 0.5 hours. (Conclusions) The proposed device made it possible to warm up and maintain the optimal engine start temperature. In 0.5 hours, we received an economic effect in the amount of 38.5 thousand rubles.

Atomic simulation of surface damage of fused silica under laser irradiation

Fused silica optical element is the core component of the inertial confinement nuclear fusion ignition device. Due to the requirement of ignition conditions of the device for high power laser, the damage to fused silica optical element under strong laser is the key to restricting the operation of the ignition device. Therefore, the study of the surface damage of fused silica irradiated by laser is crucial to the development of the ignition device for inertial confinement nuclear fusion. In this paper, large-scale non-equilibrium molecular dynamics simulation method and micro-structure analysis technology suitable for dynamic process are proposed to study the damage process of fused silica surface under laser loading. Based on the theoretical study of high-temperature plasma fireball model, the damage of high-temperature fused silica plasma ball to surface is simulated. By tracking the local structure, temperature distribution and surface morphology, the factors affecting the surface damage of fused silica are analyzed. Our research results show that the size, distance from the surface, and temperature of high-temperature fused silica balls have important effects on the surface damage. We find that there are two different damage modes under the combined effect of the above factors. One is related to a rapid damage process, generating U-shaped voids and no further obvious damages after the surface spraying, and the other is dependent of a slow damage process: continuously expanding and resulting in a larger damage area. The surface morphologies formed by these two damage modes are consistent with the two typical damage morphologies observed in the experiments. This research can provide a guidance for understanding the complex damage process in fused silica under laser irradiation.

Experimental research on flammability characteristics and ignition conditions of hybrid mixture emissions venting from a large format thermal failure lithium-ion battery

When the concentration of gas is below its lower flammable limit and the content of the particles is below its minimum explosible concentration, it can be explosible. Thermal abuse tests for 50 Ah lithium-ion batteries were conducted under an inert atmosphere. The battery failure venting emissions were collected and their composition was identified previously. It still needs further research for the flammability characteristics and ignition conditions for hybrid mixture emissions venting from a large format lithium-ion battery thermal failure. In this study, the likelihood, severity, and kinetics of the batteries' hybrid mixture emissions flammability have been researched. To analyze battery emission flammability characteristics, five indexes have been investigated; they are ignition temperature (Tig), ignition time (τig), maximum explosion pressure (Pmax), pressure rise maximum rate ((dP/dτ)max), and size-normalized maximum rate pressure rise (KSt). Based on quantitative analysis for the hybrid mixture flammability characteristics, it indicates that particle size and gas content can impact hybrid mixture emission flammability characteristics. As for the mixture with finer particles, the optimum combustion condition of the particle and gas concentration pairs were 0.3 and 0.7. The ignition temperature for the optimum combustion conditions was 495 °C. The pressure rising velocity was 23 Mpa/s during ignition. High solvent content and low particle concentration are the conditions for optimum combustion. This indicates that the gas admixture solvent plays a major role in the combustion kinetics of the mixture emission. This research offers a fundamental perspective and provides preventive and protective thermal safety designs that are more suitable for large format commercial battery thermal systems.